This invention relates generally to apparatus for electronically measuring the temperature of a living body, and more particularly, to a thermometer that exhibits enhanced conformity to the anatomy of a human being, especially in and around the mouth.
The basic mercury thermometer has been the standard for measuring body temperature for decades and is known virtually throughout the world. It consists of a hollow glass rod with a bulb of mercury at one end and a temperature scale along the glass rod. Typically, it is inserted into the mouth of a human being. Errors can of course be made in reading the temperature from the scale. Care and a certain amount of expertise are required for proper and accurate use.
From the patient's viewpoint, this form of thermometer is awkward because the thermometer must be held under the tongue. As viewed from the side, the rod of the thermometer should be inclined upwardly at an angle of about 30 degrees from the horizontal in order to operate effectively and accurately. Many patients have a natural tendency to bite down on the thermometer with their teeth. The upper teeth of most humans extend forward of the lower teeth with an overbite. When the thermometer is inserted in the mouth, it ordinarily rests on or close to the lower teeth. Thus, when a patient bites down on the thermometer, the lower teeth act as a fulcrum to apply rotational forces on the thermometer. Such rotational forces tend to dislodge the thermometer from under the tongue, usually up to and against the palate. This requires that the thermometer be relocated back under the tongue. To avoid this problem, some patients extend their lower jaw so that the lower teeth are forward of the upper teeth. However, this extension of the lower jaw is unnatural and uncomfortable.
Electronic thermometers have been introduced which emulate the linear structure of the basic mercury thermometer. A numerical display is usually disposed on electronic thermometers to assist in reading the measured temperature. Electronic thermometers also avoid any potential mercury exposure issues associated with a mercury thermometer. These electronic thermometers have a temperature sensing tip at one end for insertion under the tongue, an intermediate linear shaft and an enlarged body or housing at the end opposite from the sensing tip. The enlarged housing contains electronics for translating a temperature signal from the sensing tip into the currently measured temperature. Typically, the enlarged housing also contains a display, such as of the liquid crystal display (LCD) type, for displaying the measured temperature. The enlarged housing also contains a source of electrical power, such as a miniature battery.
Such electronic thermometers with digital displays offer improved convenience and accuracy compared to reading the linear scale of the basic mercury thermometer. However, these linear electronic thermometers exacerbate the problems of keeping the tip of the thermometer under the tongue due to the increased moments of inertia presented by the additional weight and mass of the enlarged housing at the opposite end of the thermometer. This problem can be particularly acute in. patients unused to, or uncooperative in, having their temperature taken, such as children or the elderly.
Hospitals and other institutions use thermometers of different designs. Typically, a hospital thermometer has a linear probe that is placed under a patient's tongue in order to read the patient's temperature. The probe is usually detached from the housing portion of the thermometer where the electronics are housed and where the read-out of the patient's temperature is displayed. This detached probe design helps to keep the thermometer clean and sanitized by avoiding contact with the sick patient. The detached probe also allows a caregiver to read the temperature of a patient on a LCD screen that is in close proximity to the caregiver and not in close proximity to the sick patient's mouth. These types of thermometers necessitate that the patient keep the linear probe under the tongue in the correct position for the appropriate period of time, often for 30 seconds or more. The linear probe of a hospital thermometer presents the same limitations as discussed above in that it is uncomfortable and is difficult to keep positioned in the mouth and under the tongue in the correct position for temperature taking. People who are ill, and the elderly have even a more difficult time keeping the probe positioned properly. The thermometer must be held in position for the requisite time period to produce an accurate reading. When the patient shifts the probe away from the hot spot under the tongue, the reading time is increased and the accuracy of the reading is compromised. In hospital settings it is often necessary to obtain precise temperature readings in order to properly diagnose and monitor a patient. Therefore, the existing hospital thermometers present the problems of being uncomfortable, slow and inaccurate.